Explore relationships

Johnny Galecki

John Mark Galecki (born April 30, 1975) is an American actor. On television, he played Leonard Hofstadter on The Big Bang Theory (2007–2019) and David Healy in Roseanne (1992–1997; 2018) and The Conners (2018–2019).

Use + to expand a branch. Click a topic name to open its summary.